This invention relates generally to grinding machines and more particularly concerns the storage of diamond polishing pads used in grinding machines.
Grinding machines, such as floor grinders, typically utilize sets of diamond polishing pads mounted in subsets on the machine. Each subset is orbited about its own axis and each pad of a subset is spun about its own axis. The pads consist of diamond chips suspended in a phenolic or metallic medium so that, as the pad spins and orbits on the surface to be polished, the medium is worn away and the diamond chips cut the surface. The grit of the pads is determined by the size of their diamond chips. The pads are removably attached to the machine, for example by screws or by mating segments of hook-and-loop material. The pads are replaced when they are worn out or whenever a different grit is required. Since the pads are relatively expensive, used pads which are not worn out are saved for future polishing tasks. In practice, this generally means that the pads are detached from the machine and tossed into a common storage bucket containing other pads of various grit and in various states of wear for retrieval when their grit is appropriate to a future task.
In the grinding process, the pads are spun and orbited at extremely high speeds. The more the grinding surfaces deviate from a common plane or from a plane parallel to the plane of balanced weight of the machine, the less control the operator has over the machine. Loss of control makes the task more difficult, increases the wear rate of the pads and may also result in damage to the surface being polished. Consequently, it is necessary for the operator to sort through the pads to find pads of the desired grit and then to assess the wear condition of those pads to assemble a set in which all of the pads are of substantially the same thickness. Grits may vary over a range extending from 12 to 3500 and it is not uncommon for multiple sets of pads in various states of wear for eight or more different grits to be collected in a common bucket. Since the pads are only in the order of ⅜″ to ¾″ thick to begin with, deviations can be difficult to see, even for operators with good vision. It is not uncommon for the sorting process to take 20 minutes or more and even a carefully selected set may not have a satisfactorily consistent thickness.
It is, therefore, an object of this invention to provide a caddy which stores used diamond polishing pads. Another object of this invention is to provide a caddy which eliminates the need for sorting used diamond polishing pads into matched sets. Yet another object of this invention is to provide a caddy which reduces the time spent in changing used diamond polishing pads on a grinding machine. It is a further object of this invention to provide a caddy which stores used diamond polishing pads in matched sets according to grit. Still another object of this invention is to provide a caddy which stores used diamond polishing pads in matched sets according to wear.